This invention relates to a process for the production of a milk powder.
There are various known processes for the production of milk powders which, in the interests of simplicity, may be divided into two groups according to the characteristics which it is desired to give the powders.
A first group is concerned above all with maintaining the nutritional and organoleptic qualities of the starting milk and obtaining good keeping properties and, if desired, instantaneous reconstitution and dissolution in water. This requires a careful treatment, a low content of free fats, the presence of lactose generally in amorphous form and an aerated structure. Spray-drying processes generally satisfy these requirements apart from the instant quality which may be obtained in particular by a following agglomerating treatment. The powders obtained may be directly used.
A second group is more concerned with obtaining a compact structure, a high content of free fats and, if desired, an aromatic note emanating from the Maillard reaction.
Hitherto, it has only been possible to obtain these properties by the roller drying processes described, for example, in French patent no. 2 077 611 or British patent no. 1 280 051. The powders made in this way are intermediate products used in the preparation of sauces, desserts, biscuits, confectionery and chocolate goods.
Drying on rollers has certain disadvantages compared with spray-drying, namely: it is more onerous and more difficult to carry out to obtain powders having constant characteristics. In addition, the lactose is in amorphous form.
To overcome these disadvantages, it is necessary, for example according to Swiss Patent No. 644 251, to resort to the subsequent treatment on rollers in the presence of fats of a milk powder which has already been spray-dried.